The lady loaned the mint the property. It is clear that the lady expected the mint to return them and the mint clearly lead her to believe that they would be returned.
"They didn't take the property, the lady gave them the property."
"The lady loaned the mint the property. It is clear that the lady expected the mint to return them and the mint clearly lead her to believe that they would be returned."
Assuming you are correct as to the lady's expectations, then IF she was the true owner of the property, and she was tricked into giving it up, that would be "larceny by trick". However, if the Mint is the true owner, the facts as to what the lady thought really don't amount to a hoot in H@ll.
A person is generally permitted to recover his or her own property from one who wrongfully possesses it by "self-help", as long as there is no breach of the peace. Tricking someone does not breach the peace.